The present invention is directed to inter-network communication. More particularly, the invention provides a method and system for Mobile Number Portability (MNP) for inter-network communication. Merely by way of example, the invention has been applied to a signaling transfer point (STP) system capable of handling calling and non-calling types of mobile communication between two networks. According to embodiments of the invention, a calling type communication can include voice, video, and multi-media communication, and a non-calling type communication can include text, data, and short message communication. But it would be recognized that the invention has a much broader range of applicability. For example, the invention can be applied to inter-network communication among multiple networks.
Mobile Number Portability (MNP) technology is one of fundamental requirements for network development. In particular, the implementation of MNP over the calling network has already become a mainstream practice in the industry. For example, ETSI 0366 standardizes the MNP process within G network (GSM network) and between G networks, including calling type and non-calling type processes. Moreover, Number Portability (NP) in C network (CDMA network) also has related specifications. However, there has not been an NP process that is capable of handling the non-calling type communication. Furthermore, none of the above specifications have been able to resolve MNP between different networks, for example, between a CDMA network (C network) and a GSM network (G network).
FIG. 1 is a diagram of a conventional method for inter-network communication. As shown, a conventional technique for performing NP between CDMA network and GSM network utilizes a Transit Mobile Switching Center (TMSC) 101. After TMSC receives a call, it first requests C network Home Location Register (HLR) 112 for an address. If the called user NP has reached the GSM network, then C network HLR will be unable to find the user information, and it will send an ERROR. After receiving the ERROR message, TMSC contacts G network HLR 122 for addressing based on the configuration, and finally establishes the call.
FIG. 2 is a diagram of another conventional method for inter-network communication. As shown, the method adopts a Signal Transfer Point (STP) to carry out protocol conversion to achieve MNP between CDMA and GSM networks. An example of an STP may be an SG7000 system from Huawei Technologies, Ltd. After STP intercepts Loc_reg messages, it queries an NPDB database (Number Portability Database, not shown). If it is found that the called user NP reached the GSM network, then after STP receives Sri_ack returned by HLR, it converts the message as a Loc_reg ack message and sends it back to the calling VMSC. The calling VMSC then initiates the call again based on the roaming number included in the Loc_req message. These conventional methods have many limitations as discussed below.